Abstract

The hindsight bias occurs when people judge the outcome of an
event as more predictable after the event has already happened. Participants (N =
45) completed two inattentional blindness tasks, in which an unexpected object
appeared while participants performed a primary task. Participants were asked if
they noticed the unexpected object. They were then shown the unexpected object
and asked how many people (out of 100) they thought would be able to see it. For
both tasks, those who saw the objects (Task 1: n = 5; Task 2: n = 19) judged that
more people would see it (overall: M = 39.8, SD = 23.0) than those who did not
(overall: M = 17.1, SD = 14.6). This finding is consistent with a hindsight bias:
those who experienced seeing the object thought that others would see it, while
those who did not, thought others would not.